The present invention is an improvement on my previous U.S. Pat. No. 3,450,194 issued June 17, 1969 for Greenhouse Air-Cooling System, which required expensive excavation to provide the swimming-pool-like tank for producing in winter the ice used in cooling the greenhouse atmosphere in the summertime. Furthermore, the previous tank with its uninsulated walls below ground was subject to much more heat from the surrounding ground reaching and melting the stored ice in the tank, hence required a much larger tank than the present above-ground insulated tank.